Indigenous tribes have responded to Philippines President Rodrigo Duterte’s threat to bomb their schools because he believes they’re teaching “subversion and communism.”

Duterte made the threats against the native, non-muslim, Lumad people from the southern island of Mindinao.

“Get out of there, I’m telling the Lumads now. I’ll have those bombed, including your structures,” he said in a press conference on Monday, according to AP.

“I will use the armed forces, the Philippines Air Force. I’ll really have those bombed… because you are operating illegally and you are teaching the children to rebel against government.”

The comments came after the breakdown of peace negotiations between the government and the Communist New People’s Army (NPA).

The NPA has been waging an insurgency in the Philippines for nearly 50 years and the government believes it’s using tribal areas in the countryside as its base of operations.

“The president’s statements hurt us because he does not seem to value our lives,” a Lumad spokesperson told Philippine news outlet ABS-CBN.

Indigenous leaders refuted Duterte’s allegations that they harbor communist rebels and said that the claims go back to the administration of former President Gloria Macapagal Arroyo.

US-based Human Rights Watch condemned the comments and called on Duterte to publicly retract them. They also implored the president to sign a Safe Schools Declaration to protect schools and universities from attacks during war.

Mindanao is currently under martial law due to an uprising by militants linked to Islamic State (IS, formerly ISIS/ISIL) in the city of Marawi.

Lumad groups staged a demonstration in Philippines capital Manila on Monday to call for an end to martial law on the island.

Duterte issued the threat at a press conference following his State of the Nation Address on Monday. During that speech he vowed to continue his war on drugs.

“The fight against illegal drugs will continue because that is the root cause of so much evil and so much suffering. [Drugs] weakens the social fabric and deters foreign investment from pouring in,” he said.